Covers or hoods for paper and like conditioning machines

ABSTRACT

A cover or hood for machines for the continuous production of materials in web form for paper making and board making in which the machine is totally enclosed by a frame supporting panels and horizontal and vertical peripheral tubes through which steam is circulated from a steam main and exhausted from condensate mains adjacent peripheral tubes being connected by flexible pipes.

United States Patent [1 1 Whittaker et a1.

1 1 Oct. 2, 1973 1 COVERS OR HOODS FOR PAPER AND LIKE CONDITIONING MACHINES [73] Assignees: Greenbank Engineering Company Limited, Lancaster; Easton & Johnson Limited, Taunton, both of England [22] Filed: Nov. 10, 1971 21 Appl. No.: 197,221

[30] Foreign Application Priority Data Nov. 20, 1970 Great Britain 55,197/70 [52] U.S. C1 34/201, 34/114, 34/239 [51] Int. Cl. F26b 19/00 [58] Field of Search 34/73, 114, 122, 34/155, 201, 160, 239, 240; 285/188 X [56] References Cited UNITED STATES PATENTS 3,395,458 8/1968 Whittaker et a1 34/114 1,692,498 11/1928 Gates 34/155 2,464,429 3/1949 Barksdale, Sr.,.. 34/201 2,464,119 3/1949 Dawson 34/155 3,167,408 1/1965 Justus et al. 34/122 3,623,237 11/1971 Whittaker et a1 34/201 Primary ExaminerKenneth W. Sprague Assistant Examiner-James C. Yeung Attorney.lames E. Nolan [57] ABSTRACT A cover or hood for machines for the continuous production of materials in web form for paper making and board making in which the machine is totally enclosed by a frame supporting panels and horizontal and vertical peripheral tubes through which steam is circulated from a steam main and exhausted from condensate mains adjacent peripheral tubes being connected by flexible pipes.

4 Claims, 5 Drawing Figures COVERS OR I-IOODS FOR PAPER AND LIKE CONDITIONING MACHINES This invention relates to improvements in covers or hoods for machines for the continuous production of materials in web form for paper making or board making machines.

Totally enclosed hoods have been used for many years and are manufactured from a framework covered with heavily insulated panels, the steam being generated within the hood by the drying of the paper, being mixed with a supply of hot air within the hood for vapour absorption purposes, which, in conjunction with the heavily insulated hood, avoids condensation problems within the hood.

Usually such hoods operate at a maximum dry bulb temperature in order of 145 F and 65% RH (relative humidity). It is an accepted fact that the higher the dry bulb temperature and RH which can be used within the hood, the more efficient becomes the hood from a drying point of view, and also for the purposes of utilizing the exhaust vapours for heat recovery purposes.

In our prior US. Patent No. 3395458 we have disclosed a hood or cover for the rollers of machines for the continuous treatment of material in web form with humidified air or steam wherein means are provided for independently heating the inner surfaces of the walls of the cover or hood to a sufficient temperature to prevent condensation of moisture thereon, said means comprising a series of tubes in proximity to the surfaces of the sides and top of the hood or cover, one end of each tube being connected to a common inlet manifold and the other end of each tube to a commonoutlet manifoldj the inlet manifold being in communication with a steam supply source and the outlet manifold being in communication with exhaust.

It has now been found that the hood or cover described in our previous specification may be extended to a canopy or hood for a complete machine and that the use of such a hood or canopy has enabled a dry bulb temperature of 150 F at RH figures as high as 98 percent without causing condensation within the hood or canopy.

According to the invention a cover of hood for a machine for the-continuous treatment of material in web form with 'humidifed air or steam comprises a frame carrying panels covering the top or roof, sides and ends of the frame, girders supporting the frame and a plurality of horizontal and vertical peripheral tubes extending around the frame, a steam main for supplying steam to the peripheral tubes in the top or roof and condensate mains adjacent the lower edge of the sides to exhaust the condensate, adjacent peripheral tubes being connected by flexible tubes to allow the steam to pass through the tubesfrom the steam main to the condensate mains.

The invention will be described with reference to the accompanying drawings:

FIG. 1 is a perspective view of a canopy or hood frame with the panels removed for the machine for the continuous production of materials in web form;

FIG. 2 is a part vertical section enlarged on line 2-2 FIG. I;

FIG. 3 is a part vertical section enlarged on line 33 FIG. I; 7

FIG. 4 is a detail section through a panel and a peripheral tube;

FIG. 5 is a detail vertical section on line 5-5 FIG. 1.

A hood or canopy to totally enclose a paper making or like machine of the high dew point type is provided in which the operating temperature inside the hood or canopy is 165 F dry bulb and RH or higher.

The hood or canopy is constructed with a frame I totally enclosing the machine A, composed of a plurality of panels 2 supported on girders 3 which also carry peripheral steam distribution tubes 4, preferably square in cross section, connected together at the ends of each panel by flexible pipes 5 coupled into the peripheral tubes.

The peripheral tubes 4 extend vertically and horizontally of the' side and end panels 2 of the frame 1 and along the panels of the roof which may extend to a ridge.

Steam is supplied from a steam main 6 in the roof to the peripheral tubes 4 and circulates along the peripheral tubes at the roof, sides and end frames and is exhausted through condensate mains 7 running longitudinally of the hood or canopy and extending along the lower edges of the side panels, the steam entering through flexible pipes 8 from the main 6 and leaving through the tubes through flexible pipes 9 coupled into the peripheral tubes 4 and to the condensate main 7.

The space between the outer edges of the ridge panels is enclosed by cover straps 11 extending longitudinally of the frame.

The roof panels are carried by rafters 12 supported by corner posts 13 arranged inside the frame 1. The rafters 12 are also supported on girders 16 secured thereto by plates 17, the girders 16 being carried on pillars 18 mounted on the machine frame A and reinforced by tie bars 19, 19a; additional tie rods 19b are shown between the corner posts 13 and the machine frame A.

The lowermost row of panels 2b are carried on rails 21 secured to the underside of the lowermost row of tubes 4, on runners 22 and slide in grooves 23 in a rail 24 extending around the base of the frame 1 to allow for access to the machine below the condensate mains 7.

The frame and panels are enclosed in an outer hood or cover 14 for preventing the overspill of high humidity air and the space between the outer and inner hoods may be insulated or insulated cladding 15 may be mounted directly onto the heated panels.

The tubes 4 are held in position by studs welded thereto and passing through joint cover strips 11 extending over the edges of the panels 2 and cladding l5 and secured in position by nuts on the studs (FIG. 4).

The construction of the canopy may be similar to and an extension of the hood or cover described in our earlier U.S. letters Pat. No. 3,623,237.

We claim:

1. In a hood assembly for substantially totally enclosing a machine for the continuous treatment of paper or the like in web form in a closely controlled humidity and temperature environment, the improvement comprising a plurality of, interconnected structural members defining a rigid structural frame, means for supporting said frame directly on the machine, a plurality of panels mounted on said frame to cover the top and sides thereof, vertically and horizontally extending steam distribution tube sections mounted on the panels within said hood assembly with tube sections on adjacent panels being connected by flexible tubing, a main steam pipe mounted on said frame within the upper members.

3. In the hood assembly defined in claim 1, means providing an outer hood in covering relation to said panels.

4. In the hood assembly defined in claim 1, means for mounting side panels on the lower portion of said frame for sliding movement on the frame, for access to said machine. 

1. In a hood assembly for substantially totally enclosing a machine for the continuous treatment of paper or the like in web form in a closely controlled humidity and temperature environment, the improvement comprising a plurality of interconnected structural members defining a rigid structural frame, means for supporting said frame directly on the machine, a plurality of panels mounted on said frame to cover the top and sides thereof, vertically and horizontally extending steam distribution tube sections mounted on the panels within said hood assembly with tube sections on adjacent panels being connected by flexible tubing, a main steam pipe mounted on said frame within the upper part of the hood assembly and connected to supply steam to said tube sections, and a condensate main extending along a lower side portiOn of said frame and connected to receive exhaust steam from said tube sections.
 2. In the hood assembly defined in claim 1, said frame comprising a plurality of structural roof members for extending over the top of the machine, and said means for supporting the hood assembly on the machine comprising a plurality of posts depending from said roof members.
 3. In the hood assembly defined in claim 1, means providing an outer hood in covering relation to said panels.
 4. In the hood assembly defined in claim 1, means for mounting side panels on the lower portion of said frame for sliding movement on the frame, for access to said machine. 